Optical studies on bismuth chalcogenides. (2019)

• Record Type: Journal Article
• Authors: Gupta, Sandeep; Singh, Rini; Anoop, MD.; Mathur, Dhirendra; Ray, Kanad; Kothari, S.L; Awasthi, Kamlendra; Kumar, Manoj
• Is Part Of: Materials today. Volume 10:Part 1(2019)
• Page Start: 142
• Page End: 150
• Publication Date: 2019
• Subjects: Bismuth Chalcogenides -- Optical Filters; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2019.02.199
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Films of bismuth telluride (Bi2 Te3 ) and its selenium (Se) derivatives (Bi2 SeTe2, Bi2 Se2 Te, Bi2 Se3 ) were deposited using electrodeposition on indium tin oxide coated glass substrate (ITO). The structural, morphological and optical properties of the prepared films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), raman spectroscopy and UV-Visible spectroscopy. Nanostructured polycrystalline films with rhombohedral crystal structure were obtained. Substitution of Se in place of Te does not induce any structural transition but changes the lattice parameters systematically with Se content. However, a new Raman band is observed around 235 cm -1 for intermediate compositions while the end members exhibit only E 2 g band. Wavelength selective optical transmission proportional to selenium concentration is observed in UV-Vis spectroscopy studies.